Vehicle operators are increasingly using mobile cellular phones and/or other mobile devices that are carried with them while the operators are present inside their vehicles. However, a vehicle operator may start a new vehicle trip while unintentionally leaving his of her mobile device behind, and may not notice that the mobile device is not present inside the vehicle until the vehicle is at a distance from the vehicle departure location. And, while automatic detection of mobile phones and other wirelessly-communication mobile devices is known, the systems using such detection are typically used to provide a vehicle or mobile device service to the user only after successful detection of the device in the vehicle.